1. Field
Example embodiments relate to a resistance memory device and a method of manufacturing the same. Other example embodiments relate to a resistance random access memory (RRAM) device driven at a lower power and a method of manufacturing the same.
2. Description of the Related Art
RRAMs mainly use characteristics (resistance change characteristics) by which resistance values vary with voltages of transition metal oxides and include central oxide layers and upper and lower electrodes. Referring to FIG. 1A, a memory device 10 may include a lower electrode 11, an oxide layer 12, and an upper electrode 13 sequentially stacked. The oxide layer 12 may operate as a memory node and may be made of a metal oxide having a variable resistance characteristic, for example, ZnO, TiO2, Nb2O5, ZrO2 and/or NiOx.
A RRAM using NiOx, ZrOx and/or Nb2O5-x may be a volatile memory having a higher switching endurance characteristic, retention characteristic, and other similar characteristics. Various materials for the RRAM have been studied. FIG. 1B is a graph illustrating a current-voltage characteristic of a conventional resistance memory device using NiOx as a memory node. As shown in FIG. 1B, a current of about 3 mA or more may be required to operate the conventional resistance memory device. In other words, the conventional resistance memory device may operate at a voltage and current having predetermined or given values and/or values higher than the predetermined or given values. The current may be lowered and if this occurs, the conventional resistance memory device may consume a smaller amount of power. Accordingly, there may be a need for lower power consumption of resistance memory devices, as is true for other types of memory devices.